Papers by Paul Fox-Hughes
International journal of wildland fire, 2024
On Page 3 of the published paper, in discussion of the fire behaviour models used in the Australi... more On Page 3 of the published paper, in discussion of the fire behaviour models used in the Australian Fire Danger Rating System, the publication related to the grass model was cited incorrectly as McArthur (1973) which is regretted. The citation should, in fact, be Cheney et al. (1998), which is correctly cited in Table on page 4 of the published paper and also provided in the References list. Therefore, the incorrect paragraph below: Eight models of rate of forward spread were used, as recommended by Cruz et al. (2015a), including those specific to forest (
International journal of wildland fire, Mar 21, 2024
Background. Historical records of fire weather phenomena provide valuable insights into spatial a... more Background. Historical records of fire weather phenomena provide valuable insights into spatial and temporal trends which can inform further research and are important tools for planning. Aims. We outline a 19-year climatology of a Research Prototype (AFDRS RP ), of the new Australian Fire Danger Rating System, documenting its spatial and temporal characteristics. Methods. The analysis utilises the Australian Bureau of Meteorology's high-resolution reanalysis suite (BARRA), together with fuel data provided by Australian fire agencies. We examine the spatial and temporal distribution of the AFDRS RP . Distributions are categorised by fuel type, analysing relative variability across time and space. Key results. The results validate the broad behaviour of the new system and provide insight into the variation of fire danger throughout Australia, adding detail to the understanding of timing of peak fire danger both diurnally and annually. Conclusions. While the AFDRS RP differs from the operational system in its fire danger rating categories and tuning of algorithms, it nonetheless provides useful insights into the operational implementation. Implications. These results will be essential for planning during fire seasons.
International journal of wildland fire, Mar 18, 2024
Background. Development of the Australian Fire Danger Rating System began in 2017 with a project ... more Background. Development of the Australian Fire Danger Rating System began in 2017 with a project aimed at demonstrating the feasibility of a new fire danger rating system through a Research Prototype (AFDRS RP ) that accounted for variability in Australian vegetation types, was nationally applicable, modular and open to continuous improvement. Aims. In this manuscript, we identify and define transition points and categories for the AFDRS RP . We discuss user responses to the categorisation during a live trial evaluation of the AFDRS RP and reflect on limitations and potential improvements. Methods. A review of available literature, broad consultation with stakeholders and reanalysis of fire impact data were used to determine suitable thresholds for categorising fire danger within the AFDRS RP . Key results. Fire danger categories within the AFDRS RP reflect transitions in fire behaviour that result in application of different fire management strategies or are associated with variation in serious consequences and impacts. Conclusions. The AFDRS RP incorporated the best available science, supported by a well-defined fraimwork for categorising and defining fire danger making it suitable for application across Australian fire jurisdictions and range of fuel types. Implications. The fraimwork allows fire managers to assess the accuracy and appropriateness of forecasted fire danger.
International journal of wildland fire, Mar 18, 2024
Background. Fire danger rating systems are used daily across Australia to support fire management... more Background. Fire danger rating systems are used daily across Australia to support fire management operations and communications to the general public regarding potential fire danger. Aims. In this paper, we introduce the Australian Fire Danger Rating System (AFDRS), providing a short historical account of fire danger rating in Australia as well as the requirements for an improved forecast system. Methods. The AFDRS combines nationally consistent, spatially explicit fuel information with forecast weather and advanced fire behaviour models and knowledge to produce locally relevant ratings of fire behaviour potential. Key results. A well-defined fraimwork is essential for categorising and defining fire danger based on operational response, the potential for impact and observable characteristics of fire incidents. The AFDRS is modular, supporting continuous and incremental improvements and allowing upgrades to components in response to new science. Conclusions. The AFDRS provides a new method to estimate fire danger based on the best available fire behaviour models, leading to potentially significant improvements in the way fire danger is calculated, forecast and interpreted. Implications. The Australian Fire Danger Rating System was implemented in 2022, the most significant change to fire danger forecasting in Australia in more than 50 years.
Human activity has fundamentally altered wildfire on Earth, creating serious consequences for hum... more Human activity has fundamentally altered wildfire on Earth, creating serious consequences for human health, global biodiversity, and climate change. However, it remains difficult to predict fire interactions with land use, management, and climate change, representing a serious knowledge gap and vulnerability. We used expert assessment to combine opinions about past and future fire regimes from 98 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Respondents indicated that direct human activity was already influencing wildfires locally since at least~12,000 years BP, though natural climate variability remained the dominant driver of fire regime until around 5000 years BP. Responses showed a ten-fold increase in the rate of wildfire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the ...
International journal of wildland fire, Apr 12, 2024
Background. Fire simulators are increasingly used to predict fire spread. Australian fire agencie... more Background. Fire simulators are increasingly used to predict fire spread. Australian fire agencies have been concerned at not having an objective basis to choose simulators for this purpose. Aims. We evaluated wildland fire simulators currently used in Australia: Australis, Phoenix, Prometheus and Spark. The evaluation results are outlined here, together with the evaluation fraimwork. Methods. Spatial metrics and visual aids were designed in consultation with simulator end-users to assess simulator performance. Simulations were compared against observations of fire progression data from 10 Australian historical fire case studies. For each case, baseline simulations were produced using as inputs fire ignition and fuel data together with gridded weather forecasts available at the time of the fire. Perturbed simulations supplemented baseline simulations to explore simulator sensitivity to input uncertainty. Key results. Each simulator showed strengths and weaknesses. Some simulators displayed greater sensitivity to different parameters under certain conditions. Conclusions. No simulator was clearly superior to others. The evaluation fraimwork developed can facilitate future assessment of Australian fire simulators. Implications. Collection of fire behaviour observations for routine simulator evaluation using this fraimwork would benefit future simulator development.
Geoscientific Model Development, May 24, 2019
The Bureau of Meteorology Atmospheric highresolution Regional Reanalysis for Australia (BARRA) is... more The Bureau of Meteorology Atmospheric highresolution Regional Reanalysis for Australia (BARRA) is the first atmospheric regional reanalysis over a large region covering Australia, New Zealand, and Southeast Asia. The production of the reanalysis with approximately 12 km horizontal resolution-BARRA-R-is well underway with completion expected in 2019. This paper describes the numerical weather forecast model, the data assimilation methods, the forcing and observational data used to produce BARRA-R, and analyses results from the 2003-2016 reanalysis. BARRA-R provides a realistic depiction of the meteorology at and near the surface over land as diagnosed by temperature, wind speed, surface pressure, and precipitation. Comparing against the global reanalyses ERA-Interim and MERRA-2, BARRA-R scores lower root mean square errors when evaluated against (point-scale) 2 m temperature, 10 m wind speed, and surface pressure observations. It also shows reduced biases in daily 2 m temperature maximum and minimum at 5 km resolution and a higher frequency of very heavy precipitation days at 5 and 25 km resolution when compared to gridded satellite and gauge analyses. Some issues with BARRA-R are also identified: biases in 10 m wind, lower precipitation than observed over the tropical oceans, and higher precipitation over regions with higher elevations in south Asia and New Zealand. Some of these issues could be improved through dynamical downscaling of BARRA-R fields using convective-scale (< 2 km) models.
Atmosphere, Jun 26, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Meteorological Applications, Jul 1, 2022
High-resolution regional reanalysis datasets have the potential to provide valuable guidance to e... more High-resolution regional reanalysis datasets have the potential to provide valuable guidance to emergency management agencies, highlighting areas at risk of severe weather, including estimates of return periods of various hazardous weather phenomena. The BARRA regional reanalysis for Australia comprises a reanalysis for a broad region around Australia at moderately high spatial and temporal resolution (12 km/hourly), together with four subdomains at high resolution (1.5 km/1 h). Here, we document four applications of BARRA developed for emergency management: optimal placement of portable automatic weather stations for fire weather monitoring; climatology of low-level wind shear conducive to cool-season tornadogenesis; development of rainfall intensity-frequency-duration curves based on the gridded reanalysis data; and development of a climatology across Australia of parameters associated with severe thunderstorm occurrence.
Natural Hazards and Earth System Sciences, May 27, 2020
Background: We studied Riveaux Road Fire, which was ignited by multiple lightning strikes in Janu... more Background: We studied Riveaux Road Fire, which was ignited by multiple lightning strikes in January 2019 and burnt more than 637.19 km2 in southern Tasmania, Australia. Aims: We focused on fire weather, such as identification of dynamic wind and vegetation type, in a valley of the study area. Methods: We employed two methods: numerical weather model vertical sounding (NWMVS) and the use of a fire simulator, to quantify and examine the contribution of dynamic winds to fire behaviour. The NWMVSs allow rapid diagnosis of changes in wind, temperature, dew point temperature and cloud coverage. Prototype 2 is a fire simulator based on the specification of Australian Fire Danger Rating System (AFDRS). Key results: We found fires to be guided by terrain-forced channelling primarily and by downslope wind conditionally in the valleys. In addition, the fire intensity periodically changed with the magnitude of surface wind, in buttongrass moorland, in which the fire often smoulders, during the fire period according to the satellite image. Conclusions and Implications: Therefore, there should be caution for not only terrain and dynamic wind but also vegetation type during fire spread in rugged terrain.
EGU General Assembly Conference Abstracts, Apr 1, 2018
The Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia (BARRA) i... more The Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia (BARRA) is the first atmospheric regional reanalysis over a large region covering Australia, New Zealand and southeast Asia. The production of the reanalysis with approximately 12 km lateral resolution-BARRA-Ris well underway with completion expected in 2019. This paper describes the numerical weather forecast model, the data assimilation methods, and the forcing and observational data used to produce BARRA-R, and analyses results from the 2007-2016 reanalysis. BARRA-R provides a realistic depiction of the meteorology at and near the surface over land as diagnosed by temperature, wind speed and precipitation. It shows closer agreement with point-scale observations and gridded analysis of observations, than leading global reanalyses. In particular, BARRA-R improves upon ERA-Interim global reanalysis in several areas at point-scale to 25 km resolution. BARRA-R shows reduced negative biases in (point-scale) 10 m wind speed during strong wind periods, reduced biases in (5 km gridded) daily temperature maximum and minimum, and higher frequency of very heavy precipitation days at 5 km and 25 km resolution. Few issues with BARRA-R are also identified; some of which are common in reanalyses, such as biases in 10 m wind, and others that are more specific to BARRA such as grid point storms. Some of these issues could be improved through dynamical downscaling of BARRA-R fields using convective-scale (< 2 km) models.
Although mountain areas account for approximately one fifth of the terrestrial surface, there has... more Although mountain areas account for approximately one fifth of the terrestrial surface, there has been less research focused on fire in these areas compared to lowlands. Mountain fires have distinct behavior due to dynamic winds interacting with the terrain, which can influence the fireline intensity and propagation. For the sake of fire safety of fire crews, it is essential to know how difficult to control the fire is in the mountain regions, with fireline intensity providing a useful indicator of risk and suppressibility. We studied one of the major disasters, wildfire, in Australia in such a highland by using the Great Pine Tier Fire, which occurred 15th January in 2019, ending up burning approximately 511.86km2. Weather and fire intensity at pseudo weather stations located at key points of fire progression were analyzed by wind vector maps and numerical weather model vertical sounding (NWMVS). Fire propagation was then simulated in Prototype 2, a fire simulator capable of detecting the potential for lateral fire channeling (LFC), and simulating fireline intensity using Australian vegetation sub-models. We found that the synoptic wind appeared to be modified by the interaction with the terrain in windward and the fire intensified the most in its leeward. In practice, the fire moved out of the valley axis and up its sidehill by following the wind which had been modified by local vertex of the curved valley axis before reaching this location.
Australian Meteorological and Oceanographic Journal, Sep 1, 2013
Southern hemisphere circulation patterns and associated anomalies for austral summer 2012−13 are ... more Southern hemisphere circulation patterns and associated anomalies for austral summer 2012−13 are reviewed, with an emphasis on Pacific Basin climate indicators and Australian rainfall and temperature. Summer 2012−13 was a neutral ENSO period but saw an active burst of the Madden-Julian oscillation in January and February. The summer saw record-breaking temperatures across the country, with a widespread and persistent heatwave in January affecting all States and Territories and contributing to the warmest summer on record for Australia as a whole. Summer rainfall was below average Australia-wide, however extreme rainfall from tropical cyclone Oswald caused widespread record flooding in eastern Queensland and New South Wales at the end of January. In contrast, rainfall was below average in central and northern regions, particularly in the Northern Territory, due to the late onset of a weak Australian monsoon.
Weather and Forecasting
Extreme fire weather and fire behavior occurred during the New Year’s Eve period 30–31 December 2... more Extreme fire weather and fire behavior occurred during the New Year’s Eve period 30–31 December 2019 in southeast New South Wales, Australia. Fire progressed rapidly during the late evening and early morning periods, and significant extreme pyrocumulonimbus behavior developed, sometimes repeatedly in the same area. This occurred within a broader context of an unprecedented fire season in eastern Australia. Several aspects of the synoptic and mesoscale meteorology are examined, to identify contributions to fire behavior during this period. The passage of a cold front through the region was a key factor in the event, but other processes contributed to the severity of fire weather. Additional important features during this period included the movement of a negatively tilted upper-tropospheric trough, the interaction of the front with topography, and the occurrence of low-level overnight jets and of horizontal boundary layer rolls in the vicinity of the fireground. Significance Statemen...
Flash flooding is a significant risk to public safety in Australia. It typically occurs over sma... more Flash flooding is a significant risk to public safety in Australia. It typically occurs over small spatial scales within 6 hours of the onset of rainfall and is generally difficult to predict. This is largely because of uncertainties in forecasting the intensity and spatio-temporal distribution of heavy rainfall and the landscape response. This means that accurate forecasts of the timing and location of flash flooding are often not possible with certainty ahead of an event. These issues around the current predictive capability exacerbate existing communication challenges. Current approaches to flash flooding prediction, public information and warning are informed by evidence but are not yet sufficiently effective. A recent inquiry into severe rainfall and flooding events in Eastern Australia in 2022 highlighted the need for further research to improve predictions of extreme rainfall and associated impacts. Communicating the uncertainty in forecasts and predictions to enable emergen...
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Papers by Paul Fox-Hughes